With babies and small infants it is necessary to provide milk, such as expressed or formula milk, or other liquids, at a predetermined temperature above room temperature. Such milk is generally heated in a baby bottle or the like before being fed to a baby. Whilst it is relatively simple to heat the contents of a baby bottle at home, it can be difficult to find the facilities to heat contents of a baby bottle in other circumstances.
One way of preparing the contents of a baby bottle is to submerge at least part of a baby bottle containing the liquid in hot water. Therefore, it is known to transport hot water in a vacuum flask, also known as a Thermos™. Vacuum flasks are able to retain water or another liquid received in the flask at a temperature above the surrounding temperature for a sustained period of time. This water may then be poured into a container in which a baby bottle is placed to heat the contents of the baby bottle when desired.
Vacuum flasks generally have a lid which is removable to allow liquid to be fed into the flask and is openable to allow liquid to be poured from the flask. However, it has been recognised that it is easily forgotten to close the vacuum flask after use. This is particularly acute when the vacuum flask has a lid which is openable and closable without having to remove the lid because it may be difficult to immediately recognise whether a lid is sealed or unsealed. It is not easy to stay calm and focus on safely storing the flask containing a hot liquid, when a baby is crying or when a large number of items have to be packed. A user may forget to close the fluid passageway, causing unwanted spill of liquid, which may result in wet items and burns.